The Application of Ers Sar Interferometry for the Assessment of Hazards Related to Slope Motion and Subglacial Volcanism

Methods and applications of ERS SAR interferometry for monitoring mass movements on mountain slopes and surface deformation in volcanic areas have been investigated in order to explore the operational potential of interferometry for the assessment of natural hazards. A statistical analysis was carried out in a region of the Eastern Alps to study the potential of SAR for monitoring slope motion in dependence of topographic factors and coherence. Case studies at slopes with movements of millimetres to centimetres per year provided further evidence for the capability of InSAR to monitor the creep of unstable slopes. The method is well applicable in high alpine areas where the coherence is preserved over annual intervals, whereas at lower elevations the applicability decreases significantly due to phase decorrelation over vegetated area. ERS tandem data of western Vatnajökull in Iceland formed the basis for studying the application of InSAR for monitoring glacier phenomena, which are related to subglacial geothermal and volcanic activity and may cause hazardous water outbreaks. The data provide area-detailed information on dynamic features such as the ice deformation after a volcanic eruption, the vertical displacement of ice above subglacial lakes, and temporal changes of the ice flow of glaciers indicating changes of the hydraulic regime. The ERS tandem data are of great value for scientific studies of ice dynamic phenomena to improve the understanding of glaciers in volcanic regions.